feat: add --user flag to install.sh for user-local installation (#586)

* Initial plan

* Add --user flag to install.sh for user-local installation

Co-authored-by: bytemain <13938334+bytemain@users.noreply.github.com>

* Improve code quality: use POSIX-compliant pattern matching and reduce duplication

Co-authored-by: bytemain <13938334+bytemain@users.noreply.github.com>

* Remove trailing whitespace

Co-authored-by: bytemain <13938334+bytemain@users.noreply.github.com>

* Improve shell detection and fish instructions

Co-authored-by: bytemain <13938334+bytemain@users.noreply.github.com>

* Update documentation with --user flag usage

Co-authored-by: bytemain <13938334+bytemain@users.noreply.github.com>

* Use $INSTALL_DIR variable instead of hardcoded path in fish instructions

Co-authored-by: bytemain <13938334+bytemain@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: bytemain <13938334+bytemain@users.noreply.github.com>

Author: Copilot

docs/guides/quick-start.md

@@ -71,6 +71,19 @@ sudo yum install vfox
 $ curl -sSL https://raw.githubusercontent.com/version-fox/vfox/main/install.sh | bash
 ```
 
+**User-local Installation (no sudo required)**
+
+If you want to install `vfox` to your user directory (`~/.local/bin`) instead of system-wide, use the `--user` flag. This is particularly useful for environments where you don't have sudo access or where system directories are ephemeral (e.g., Coder workspaces):
+
+```shell
+$ curl -sSL https://raw.githubusercontent.com/version-fox/vfox/main/install.sh | bash -s -- --user
+```
+
+This will:
+- Install `vfox` to `~/.local/bin` (no sudo required)
+- Automatically create the directory if it doesn't exist
+- Provide instructions to add `~/.local/bin` to your `PATH` if needed
+
 :::
 
 ## 2. Hook `vfox` to your `Shell`

docs/zh-hans/guides/quick-start.md

@@ -72,6 +72,19 @@ sudo yum install vfox
 $ curl -sSL https://raw.githubusercontent.com/version-fox/vfox/main/install.sh | bash
 ```
 
+**用户级安装（无需 sudo）**
+
+如果您想将 `vfox` 安装到用户目录（`~/.local/bin`）而不是系统范围内，请使用 `--user` 标志。这对于没有 sudo 访问权限或系统目录为临时目录的环境（例如 Coder 工作区）特别有用：
+
+```shell
+$ curl -sSL https://raw.githubusercontent.com/version-fox/vfox/main/install.sh | bash -s -- --user
+```
+
+此命令将：
+- 将 `vfox` 安装到 `~/.local/bin`（无需 sudo）
+- 如果目录不存在，会自动创建
+- 如果需要，会提供将 `~/.local/bin` 添加到 `PATH` 的说明
+
 :::
 
 ## 2. 挂载`vfox`到你的`Shell`

install.sh

@@ -1,6 +1,21 @@
 #!/bin/bash
 
 main() {
+  # Parse command-line arguments
+  USER_INSTALL=false
+  for arg in "$@"; do
+    case "$arg" in
+      --user)
+        USER_INSTALL=true
+        ;;
+      *)
+        echo "Unknown argument: $arg"
+        echo "Usage: $0 [--user]"
+        exit 1
+        ;;
+    esac
+  done
+
   # Detect if running in Termux
   IS_TERMUX=false
   case "${HOME:-}" in
@@ -11,7 +26,11 @@ main() {
   esac
 
   # Set installation directory and sudo command based on environment
-  if [ "$IS_TERMUX" = true ]; then
+  if [ "$USER_INSTALL" = true ]; then
+    INSTALL_DIR="${HOME}/.local/bin"
+    SUDO_CMD=""
+    echo "Installing to user directory: $INSTALL_DIR"
+  elif [ "$IS_TERMUX" = true ]; then
     INSTALL_DIR="${PREFIX}/bin"
     SUDO_CMD=""
   else
@@ -105,6 +124,60 @@ main() {
   rm $TAR_FILE
   rm -rf $FILENAME
   echo "vfox installed successfully!"
+
+  # Check and update PATH if installing to user directory
+  if [ "$USER_INSTALL" = true ]; then
+    # Check if ~/.local/bin is in PATH using POSIX-compliant pattern matching
+    case ":$PATH:" in
+      *":$INSTALL_DIR:"*)
+        echo "$INSTALL_DIR is already in your PATH."
+        ;;
+      *)
+        echo ""
+        echo "WARNING: $INSTALL_DIR is not in your PATH."
+        echo "To add it to your PATH, run one of the following commands based on your shell:"
+        echo ""
+
+        # Common export command for bash/zsh
+        PATH_EXPORT_CMD='export PATH="$HOME/.local/bin:$PATH"'
+
+        # Detect the current shell more reliably than using $SHELL alone
+        if command -v ps >/dev/null 2>&1; then
+          CURRENT_SHELL=$(ps -p "$$" -o comm= 2>/dev/null | tr -d ' ')
+        fi
+        if [ -z "$CURRENT_SHELL" ] && [ -n "$SHELL" ]; then
+          CURRENT_SHELL=$(basename "$SHELL")
+        fi
+
+        case "$CURRENT_SHELL" in
+          bash)
+            echo "  For bash:"
+            echo "    echo '$PATH_EXPORT_CMD' >> ~/.bashrc"
+            echo "    source ~/.bashrc"
+            ;;
+          zsh)
+            echo "  For zsh:"
+            echo "    echo '$PATH_EXPORT_CMD' >> ~/.zshrc"
+            echo "    source ~/.zshrc"
+            ;;
+          fish)
+            echo "  For fish:"
+            echo "    # Run this in a fish shell:"
+            echo "    fish_add_path $INSTALL_DIR"
+            echo "    # Or persist it by adding this line to your config:"
+            echo "    echo 'fish_add_path $INSTALL_DIR' >> ~/.config/fish/config.fish"
+            ;;
+          *)
+            echo "  For bash/zsh:"
+            echo "    echo '$PATH_EXPORT_CMD' >> ~/.bashrc  # or ~/.zshrc"
+            echo "    source ~/.bashrc  # or source ~/.zshrc"
+            ;;
+        esac
+        echo ""
+        echo "Or manually add $INSTALL_DIR to your PATH in your shell's configuration file."
+        ;;
+    esac
+  fi
 }
 
 main "$@"